Manufacture of smokeless powder propellants



Patented July 4, 1933 7 UNITED STA T E S 'jPQA OFFICE- ARTHUR. noueir, or PASSAIC, NEW aEn-sEY,jAss'Ie1\Toa TO DEGN CORPORATION, A I I CORPORATION or DELAWARE v MANUFACTURE or SMOKELESS rownnn PROPELLANTS 1 No Drawing. Application fiieanprn a, 1329, Serial no. 352,320. 'Renewed March 15,'1 933.

inventionrelates to the manufacture of smokeless powder propellants. 1

i The object .of my invention is to produce a smokeless powder. having properties superior to those now in use, also to manufacturethe new powder economically} Inthe manufacture of modern smokeless poWders,-their compositions should be such as to produce on combustion in the chamber of the gun,:qmaximum volume of gases at the j lowest temperature so as to prevent erosion of the inner surface of the gun.v Under these conditions, the desired gas pressure curve is obtained. The powder should have the maximum chemical stability, so as to preserve its original characteristics even after long storage in hot climates. It should also be of such a nature that it can be quickly prepared to meet the demand of warfare.

Service smokeless powder, as itisnow made in the several countries, consists of either one or two bases, i. e. a one base powder consists of nitro-cellulose (to which maylbe-added a small quantity of a so-called stabilizer such as diphenylamine) made into a plastic mass by a-solventsuch as acetone or ether-alcohol, and formed into grains, strips, or cords by forcing the mass through suitable dies, and afterwards carefully evaporating the solvent leaving the said grains, strips or cords in a firm but slightly elastic condition, this elastic condition is necessaryto prevent fracture in the chamber of the gun during combustion which would result in an undesirable increase of surface of the pieces of powder increasing the initial gas pressure beyond that predetermined by calculation.

Such one base powder as described above however does not possess that degree of chemical stability considered desirable for service powder, and any addition such as diphenylamine does not really render the nitrocellulose more stable and only masks the reactions going on in the powder on long storage, the reagent absorbing the products of then should be avoided, and the composition of the powder should be such as to. give great stability. .7 f g A two base powder generally consists of of the gun.

r then formed into grains, strips or cords by forcing same through dies and the solvent afterwards removed by evaporation.

In the preparation of both one and two base powders, it is absolutely necessary to evaporate the solvent very slowly to avoid distortion of the grains, strips or cords and the calculated surface of the pieces of powder must be preserved,'otherwise the ballistics of the powder would be seriously modified, and this slow removal of the solvent requires time and cannot be hurried.

i It has been found-that the addition of nitro-glycerine-has a marked eifect on increasing the chemical stability of the nitro-cellulose, and such two base powders have proved superior from'this viewpoint. Nitroglycerine however has its disadvantages inasmuch as it is a poor solvent for all grades of nitro-cellulose and 'consequently a large amount of solvent is required 'to bring the two explosives into that state necessary to form the grains, strips or cords. Another objection to nitro-glycerine is its detonating property, which, in the event of exudation of this explosive from the finished product may become a source of danger. The temperature of combustion of nitro-glycerine also is extremely high and this is an objection to its use for this purpose.

My invention relates to the use of di ethylene glycol di-nitrate having the composition CH2(NO3).GH2.O.GH2.CH2(NO3) a product resultingfrom the nitration of diethylene glycol under certain conditions, the product and process of making same specified in my applications for patents Serial Numbers 323,583 and 323,58l filed December I r 3, 1928. decomposition only. Such masking reagents Di-ethylene glycol di-nitrate is a compound of extraordinary 3 chemical stability and possesses great solvent property for nitro-cel-- lulose of wide nitrogen content range. It has also a low temperature of combustion and acetone, ether-alcoholor their equivalents to compared with nitroglycerine is practically inert as far as detonating property is concerned. I v Its solvent power for nitro-cellulose is so great that very little QXtlitSOlVQIlt is required conditionto form grains, strips'or cords, and

for some smokeless powders where the content of di-ethylene glycol di-nitrate may be high,

the extrasolvent may be entirely dispensed with. To carry out my invention'l dissolve in the di-ethylene' glycol di-nitrate the .re-

quired amount of nitrocellulose preferably keeping the material warm, adding if neces sary, suflicient extra solvent which may be bring about the condition desired, the following are good proportions for service powders r I g 7 Percent v e by weight 1. Nitro cellulose (12.78% N.') 84.85 Digethylene glycol di-nitrate 15.15

This composition gives {a powder of minimum-temperature of combustion, and maximum .gas volume. 1

I The above compositions both give excellent results. The proportlons 1n the mixtures may of course be varied betweenwide limits and the resulting products ofcombustion will,

Vary accordingly, but no matter how much the variation, the smokeless powderresulting therefrom wi ll have very excellent properties, exceedmg byfar anything nowin use. I have 7 described smokeless powder containing the twornaterials, viz-z nitro-cellulose and diethylene glycol di-nit-rate as such, but it must be understood that these may be combined.

with other substances such as nitro-glycerine sary to meet any specific requirements, and

amount or class of extra solvent may be emto bringthe two ingredients into the desired g ,sired state for forming mto gra1ns,'str 1ps or ployed to bring the ingredients into the decords, and Iconsider such additions covered .by my invention. I have given above, example mixtures that give'excellent results in allicircumstances, and the mixture specified containing, 84.85% of nitro cellulose of 12.7 8% nitrogen content, and 15.15% of diethylene glycol di-n'itrate gives as gaseous combustion inthe chamber of the gun is complete to CO, be ideal..- There are circum stances however, when hydrocarbons ortheir equivalents are employed in the mixturefor reasons mentioned above, that call for a variation of the nitrates to furnish )sufiicient oxygen to combust the'extra carbon and hydrogen contained in such additions, and this desired end maybebrought about in the manner already referred to.

1. A smokeless powder propellant, containing about to of nitrocellulose together with a small percentage of dietbylene glycol dinitrate.

2. A smokelesspropellant'powder containing about 85% to 90% of nitrocellulose, the remainder being largely composed of liquid organic nitrates including a substantial proportion of diethylene glycol dinitrate.

Signed at Passaic in the county of Passaic and State of New Jersey this 2 d d f April, 1929,; 7

,ARTHURVHOUGH. 

